Improvement in drill-rod couplings



R. .A. CLARK. Drill- Rod Ceuplings.

NO. 141,694. Patented August12,1873.

A I I 39111125525: war:

UNITED STATES PATENT OFFICE.

ROBERT A. CLARK, OF PETROLIA CITY, PENNSYLVANIA.

IMPROVEMENT IN DRILL-ROD COUPLINGS.

Specification forming part of Letters Patent No. 1 1L694, dated August 12, 1873 application filed February 1, 1873.

To all whom it may cancer-n.-

Be it known that I, ROBERT A. CLARK, of Petrolia City, in the county of Butler and State of Pennsylvania, have invented a new and Improved Drill-Rod Coupling, of which the following is a specification:

My invention consists of one sectionsay, the lower one-having a screw-threaded portion at the end of smaller size than the rod screwing into a socket'in the end of the other section by a right-hand screw, and a sleeve screwing on the two sections by a left-hand thread down against a collar on the lower section by which the joints are locked so that it cannot work loose.

Figure 1 is a sectional elevation of my improved joint, and Fig. 2 is a horizontal section taken on the line a w of Fig. 1.

Similar letters of reference indicate corresponding parts.

A represents the lower section. of the rod, an d B the upper section, to be jointed together. 0 is a collar on the lower section below the screw-threaded portion D. E is a part of the upper end of the lower section, made small enough to screw into a socket in thebwer the point where the parts D and H butt together.

Having thus described my invention, Iclaim as new and desire to secure by Letters Patcut-- The sections A B connected together by a part of one screwing into a socket of the other, and a sleeve on both screwing against a collar on one, the threads'bein g reversed as to the pitch, substantially as specified.

ROBT. A. CLARK. Witnesses:

LEMUEL DEVINNY, WALTER Rowe. 

